Camera capable of automatically compensating focal length

ABSTRACT

A camera capable of automatically compensating focal length includes a base, an adjust seat, and a lens barrel. The adjust seat includes a first ring, a second ring, and a connecting member. The first ring and the second ring are coaxially sleeved with each other and a distance is kept between the first ring and the second ring. The first ring includes a first end and a second end that are axially opposite to each other. The first end is fixed on the base. The second ring includes a third end and a fourth end that are axially opposite to each other. The third end is connected to the second end of the first ring via the connecting member. The fourth end has a first coupling part. The lens barrel has a second coupling part correspondingly coupled to the first coupling part.

CROSS-REFERENCE TO RELATED APPLICATION

This non-provisional application claims priority under 35 U.S.C. §119(a) to Patent Application No. 106145594 filed in Taiwan, R.O.C. onDec. 25, 2017, the entire contents of which are hereby incorporated byreference.

BACKGROUND Technical Field

The instant disclosure relates to a camera, in particular, to cameracapable of automatically compensating focal length.

Related Art

Different cameras are provided on the market for different uses, forexample, dashboard cameras and surveillance cameras. These cameras canbe installed in the car, on the helmet, at intersections, entrances, orexits, etc., for capturing a place to be monitored.

SUMMARY

An important concern for the camera is whether the displayed image isclear enough or not. However, due to the change of temperature, thefocus position of the camera known to the inventor may easily haveunwanted movements. For instance, the heat generated by the operation ofthe camera itself may lead an increasing temperature of the componentsinside the camera (e.g., the lens barrel, the substrate, the circuitboard), so that the components may have heat expansions. Alternatively,the increasing ambient temperature (e.g., caused by sun illumination)may also lead the increasing temperature of the components inside thecamera, so that the components may have thermal expansion. Theseconditions may possibly result the focus position of the camera to beshifted to affect the photographic resolution of the image.

In view of this, in one embodiment, a camera capable of automaticallycompensating focal length is provided. The camera comprises a base, anadjust seat, and a lens barrel. The adjust seat comprises a first ring,a second ring, and a connecting member. The first ring and the secondring are coaxially sleeved with each other and a distance is keptbetween the first ring and the second ring. The first ring comprises afirst end and a second end that are axially opposite to each other. Thefirst end is fixed on the base. The second ring comprises a third endand a fourth end that are axially opposite to each other. The third endis connected to the second end of the first ring via the connectingmember. The fourth end, with respect to the third end, is distant fromthe second end, and the fourth end has a first coupling part. The lensbarrel has a second coupling part, and the second coupling part iscorrespondingly coupled to the first coupling part.

Based on the above, when a thermal source is applied to the cameraaccording to one or some embodiments of the instant disclosure, e.g.,when the camera generates heat due to the operation of the camera itselfor when the camera is heated due to sun illumination, the first ring ofthe adjust seat can have a first axial thermal deformation and thesecond ring can have a second axial thermal deformation with a directionopposite to the first axial thermal deformation. Hence, the first axialthermal deformation and the second axial thermal deformation cancompensate the thermal deformation of the components inside the camera(e.g., the lens barrel, the base, the circuit board). Therefore, thedistance between the lens and the optical sensing member can be retainedafter the thermal source is applied to the camera, and the focal lengthfor displaying an image can be maintained to keep the quality of theimage.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will become more fully understood from the detaileddescription given herein below for illustration only, and thus notlimitative of the disclosure, wherein:

FIG. 1 illustrates a perspective view of a camera according to a firstembodiment of the instant disclosure;

FIG. 2 illustrates an exploded view of the camera of the firstembodiment;

FIG. 3 illustrates an exploded view of a camera according to a secondembodiment of the instant disclosure;

FIG. 4 illustrates an exploded view of a camera according to a thirdembodiment of the instant disclosure;

FIG. 5 illustrates an exploded view of a camera according to a fourthembodiment of the instant disclosure; and

FIG. 6 illustrates an exploded view of a camera according to a fifthembodiment of the instant disclosure.

DETAILED DESCRIPTION

FIG. 1 illustrates a perspective view of a camera according to a firstembodiment of the instant disclosure, and FIG. 2 illustrates an explodedview of the camera of the first embodiment. As shown in FIGS. 1 and 2,in this embodiment, the camera capable of automatically compensatingfocal length 1 (hereinafter simplified as “camera 1”) comprises a base10, an adjust seat 20, and a lens barrel 30. In some embodiments, thecamera 1 can be assembled on an electronic device. For example, thecamera 1 may be a camera module of a dashboard camera, a mobile phone, atablet, a notebook, or other handheld electronic devices. Alternatively,the camera 1 may be a surveillance camera, like an IP camera (networkcamera), a closed-circuit television (CCTV), or an analog surveillancecamera, etc.

As shown in FIGS. 1 and 2, in this embodiment, the adjust seat 20 is onthe base 10. In one embodiment, the base 10 may be holder made ofplastic or metal. In this embodiment, the base 10 may comprise anoptical sensing member 11. In some embodiments, the optical sensingmember 11 may be a charge-coupled device (CCD), a complementarymetal-oxide semiconductor (CMOS), or a CMOS active pixel sensor.

As shown in FIGS. 1 and 2, the adjust seat 20 comprises a first ring 21,a second ring 22, and a connecting member 23. The first ring 21 and thesecond ring 22 are coaxially sleeved with each other, and a distance(e.g., 1 mm, 2 mm, 5 mm, or 10 mm) is between the first ring 21 and thesecond ring 22. In this embodiment, the first ring 21 and the secondring 22 are circular rings, but embodiments are not limited thereto. Insome embodiments, the first ring 21 may be a rectangular ring, anelliptical ring, or rings with other shapes, and the second ring 22 maybe a rectangular ring, an elliptical ring, or rings with other shapes.Furthermore, in this embodiment, an outer diameter of the first ring 21is greater than an outer diameter of the second ring 22, and the secondring 22 is sleeved in the first ring 21 with a distance kept between thefirst ring 21 and the second ring 22. That is, the first ring 21 and thesecond ring 22 are not in contact with each other. However, thisembodiment is an illustrative embodiment, and the outer diameter of thefirst ring 21 may be less than the outer diameter of the second ring 22,so that the first ring 21 is sleeved in the second ring 22.

Further, as shown in FIGS. 1 and 2, the first ring 21 of the adjust seat20 comprises a first end 211 and a second end 212 that are axiallyopposite to each other. The axial direction in the figures is the Y-axisdirection. The first end 211 of the first ring 21 is fixed on the base10 (for example, the first end 211 is fixed on the base 10 throughgluing, threading, engaging, soldering, etc.). The second ring 22comprises a third end 221 and a fourth end 222 that are axially oppositeto each other. The fourth end 222 of the second ring 22, with respect tothe third end 221, is distant from the second end 212. That is, adistance between the fourth end 222 and the second end 212 is greaterthan a distance between the third end 221 and the second end 212. Thethird end 221 is connected to the second end 212 of the first ring 21via the connecting member 23. For example, in this embodiment, theconnecting member 23 may be tubular body that is integrally formed withthe first ring 21 and extending from the second end 212 of the firstring 21 in a radial direction. An end portion of the connecting member23 distant from the second end 212 of the first ring 21 may be assembledwith the third end 221 of the second ring 22. For example, the third end221 of the second ring 22 may be fixed with the connecting member 23 viagluing, threading, engaging, soldering, etc. In other embodiments, theconnecting member 23 may be integrally formed with the second ring 22and extending from the third end 221 of the second ring 22, embodimentsare not limited thereto.

As shown in FIGS. 1 and 2, the lens barrel 30 is assembled with thesecond ring 22 of the adjust seat 20. For example, in this embodiment,the lens barrel 30 is sleeved in the second ring 22. The fourth end 222of the second ring 22 has a first coupling part 24, the lens barrel 30has a second coupling part 31, and the second coupling part 31 of thelens barrel 30 is correspondingly coupled with the first coupling part24 and assembled on an end portion of the second ring 22. As shown inthe embodiment of FIG. 2, the first coupling part 24 is an inner threadportion, and the second coupling part 31 is an outer thread portionprovided on an outer periphery of the lens barrel 30, forcorrespondingly threading with the inner thread portion. Accordingly,the threading between the lens barrel 30 and the second ring 22 allowsthe lens barrel 30 to be rotated relative to the second ring 22 toadjust a focal length for displaying an image. As shown in FIG. 2, inone embodiment, the lens barrel 30 comprises a lens 32, and here thelens 32 comprises several optical components. In some other embodiments,the lens 32 may comprise a single optical component, but embodiments arenot limited thereto. The optical sensing member 11 of the base 10corresponds to the lens 32. Since the lens barrel 30 can be rotatedrelative to the second ring 22 to adjust the relative position betweenthe lens barrel 30 and the second ring 22, the distance between the lens32 and the optical sensing member 11 can be changed to adjust the focallength for displaying an image, but embodiments are not limited thereto.In some other embodiments, the lens barrel 30 may be fixedly connectedto the fourth end 222 of the second ring 22. For example, the lensbarrel 30 is fixed on the second ring 22 through gluing, threading,engaging, soldering, etc., and illustrative figures for theseembodiments are omitted.

In some embodiments, the first ring 21 and the second ring 22 may havethe same coefficient of thermal expansion. For example, the first ring21 and the second ring 22 may be made of the same material.Specifically, the first ring 21 and the second ring 22 may be made ofthe same metal material (e.g., copper, iron, alumina, or other alloys)or the same plastic materials (e.g., polyvinyl chloride (PVC),polypropylene (PP), polyimide (PI), or polycarbonate (PC)).Alternatively, in some embodiments, the first ring 21 and the secondring 22 may have different coefficients of thermal expansion. Forexample, the first ring 21 and the second ring 22 may be made ofdifferent materials. Specifically, the first ring 21 and the second ring22 may be made of different metal materials; for instance, the firstring 21 may be made of copper and the second ring 22 may be made ofiron. Alternatively, the first ring 21 and the second ring 22 may bemade of different plastic materials; for instance, the first ring 21 maybe made of polyvinyl chloride and the second ring 22 may be made ofpolyimide. In a further option, the first ring 21 is made of a metalmaterial and the second ring 22 is made of a plastic material, such thatthe first ring 21 and the second ring 22 can have different coefficientsof thermal expansion.

Accordingly, when a thermal source is applied to the camera 1 accordingto one or some embodiments of the instant disclosure, the first ring 21of the adjust seat 20 can have a first axial thermal deformation and thesecond ring 22 can have a second axial thermal deformation with adirection opposite to the first axial thermal deformation. Hence, theaxial thermal deformation of the rings of the camera 1 can compensatethe thermal deformation of the components inside the camera 1 (e.g., thebase 10, the optical sensing member 11, the lens barrel 30, or othercomponents). Therefore, the distance between the lens 32 and the opticalsensing member 11 can be retained after the thermal source is applied tothe camera 1, and the focal length for displaying an image can bemaintained to keep the quality of the image. Details are described inthe following paragraphs.

Taking the embodiment shown in FIG. 2 as an example, supposed that, uponleaving the factory, the camera 1 already has an optimized focal lengthfor displaying an image, e.g., the distance D between the lens 32 andthe optical sensing member 11 is already optimized (here, the distance Dis between the optical sensing member 11 and a bottom of the lens 32).When a thermal source is applied to the camera 1, e.g., when the camera1 generates heat due to the operation of the camera 1 itself or when thecamera 1 is heated due to the increasing ambient temperature (forexample, the ambient temperature increases because of sun illumination),the components inside the camera 1 (e.g., the base 10, the opticalsensing member 11, the lens barrel 30, and other components) will havethermal expansion as well as thermal deformation. Similarly, the adjustseat 20 is expanding because of the heat. Since the first end 211 of thefirst ring 21 is fixed on the base 10, the first ring 21 is extending inthe direction indicated by the arrow L1 to have a first axial thermaldeformation. Furthermore, since the third end 221 of the second ring 22is fixedly connected to the connecting member 23, the second ring 22 isextending in the direction indicated by the arrow L2 (which is oppositeto the direction indicated by the arrow L1) to have a second axialthermal deformation. Accordingly, the first ring 21 and the second ring22 are extending toward opposite directions, such that the thermaldeformation of the components inside the camera 1 (e.g., the base 10,the optical sensing member 11, the lens barrel 30, and other components)can be compensated. Therefore, positions of the lens 32 and the opticalsensing member 11 can be retained to keep the default focal length fordisplaying an image.

Taking the embodiment shown in FIG. 2 as an example again, according tothe thermal deformation of the components inside the camera 1, the firstaxial thermal deformation of the first ring 21 may be the same as ordifferent from the second axial thermal deformation of the second ring22. When the first axial thermal deformation is to be the same as thesecond axial thermal deformation, the first ring 21 and the second ring22 may have the same coefficient of thermal expansion as well as thesame length, such that the first axial thermal deformation can be equalto the second axial thermal deformation. Alternatively, the coefficientof thermal expansion of the first ring 21 may be greater than thecoefficient of thermal expansion of the second ring 22, while the lengthof the second ring 22 is greater than the length of the first ring 21,so that the first axial thermal deformation can be the same as thesecond thermal deformation. When the first axial thermal deformation isto be different from the second axial thermal deformation, the firstring 21 and the second ring 22 may have the same coefficient of thermalexpansion but different lengths, such that the first axial thermaldeformation can be different form the second axial thermal deformation.Alternatively, the first ring 21 and the second ring 22 may havedifferent coefficients of thermal expansion as well as differentlengths, so that the first axial thermal deformation can be differentfrom the second axial thermal deformation. However, it is understoodthat the foregoing embodiments are provided for illustrative purposes,the axial thermal deformation of the first ring 21 and the second ring22 is configured based on the actual thermal deformation of thecomponents inside the camera 1, according to different embodiments.

In some embodiments, the connecting member 23 of the camera 1 may havedifferent configurations. For example, FIG. 3 illustrates an explodedview of a camera 1 according to a second embodiment of the instantdisclosure. In this embodiment, the connecting member 23A is anindividual component and fixed on an end surface of the second end 212of the first ring 21 and on an end surface of the third end 221 of thesecond ring 22. Since the connecting member 23A is fixed on the endsurface of the second ring 22 and the end surface of the first ring 21,the horizontal thermal deformation of the first ring 21 and thehorizontal thermal deformation of the second ring 22 do not affect witheach other to generate errors for the assembly. Furthermore, in thisembodiment, the connecting member 23A has two grooves 231. During theassembly, the second end 212 of the first ring 21 and the third end 221of the second ring 22 are respectively inserted into the two grooves231. Hence, during the assembly of the camera 1, the time for componentsalignment can be reduced, the production efficiency can be improved, anderrors for the assembly can be avoided.

Alternatively, as shown in FIG. 4, FIG. 4 illustrates an exploded viewof a camera 1 according to a third embodiment of the instant disclosure.In this embodiment, the connecting member 23B is integrally formed withthe second ring 22 and extending from the third end 221 of the secondring 22 in a radial direction. Moreover, in this embodiment, theconnecting member 23B has one groove 231. The groove 231 is at an endportion of the connecting member 23B, so that the connecting member 23Bhas a stepped surface. A protruding block 213 is protruding from an endsurface of the second end 212 of the first ring 21, so that the endsurface of the second end 212 is a stepped surface. The protruding block213 is inserted into the groove 231, so that the contact area betweenthe connecting member 23B and the first ring 21 can be increased and thestructural strength of the assembly can be improved. In otherembodiments, the connecting member 23B may be integrally formed with thefirst ring 21 and extending from the second end 212 of the first ring 21in the radial direction, but embodiments are not limited thereto.

In a further option, as shown in FIG. 5, FIG. 5 illustrates an explodedview of a camera 1 according to a fourth embodiment of the instantdisclosure. In this embodiment, the connecting member 23C is a tubularbody and sandwiched between the first ring 21 and the second ring 22, sothat a distance can be kept between the first ring 21 and the secondring 22. Furthermore, the connecting member 23C is preferably adjacentto the second end 212 of the first ring 21 and the third end 221 of thesecond ring 22.

As shown in FIG. 6, FIG. 6 illustrates an exploded view of a camera 2according to a fifth embodiment of the instant disclosure. In thisembodiment, the first coupling part 24′ is different from that in thefirst embodiment. In this embodiment, the first coupling part 24′comprises a third ring 25 and a radial connecting member 26. The thirdring 25 comprises a fifth end 251 and a sixth end 252 that are axiallyopposite to each other. The fifth end 251 of the third ring 25 isconnected to the fourth end 222 of the second ring 22 via the radialconnecting member 26. The sixth end 252 of the third ring 25 is coupledto the lens barrel 30. The third ring 25 may be a rectangular ring, anelliptical ring, or rings with other shapes. In this embodiment, anouter diameter of the third ring 25 is less than that of the second ring22, and the third ring 25 is sleeved in the second ring 22 with adistance kept between the second ring 22 and the third ring 25.Accordingly, when a thermal source is applied to the camera 2, since thefifth end 251 of the third ring 25 is fixed on the radial connectingmember 26, the third ring 25 is extending in the direction indicated bythe arrow L3 (which is opposite to the direction indicated by the arrowL2) to have a third axial thermal deformation. The first axial thermaldeformation, the second axial thermal deformation, and the third axialthermal deformation may be different from each other. For example, thecoefficients of thermal expansion of the first ring 21, the second ring22, and the third ring 25 may be different. Accordingly, in thisembodiment, the adjust seat 20 has the axial thermal deformation of thethree rings (the first ring 21, the second ring 22, and the third ring25) to retain the focal length for displaying an image. Therefore, thisembodiment is suitable for a camera 2 with a more complex thermaldeformation situation. For example, this embodiment is suitable forcomponents inside a camera having non-linear thermal deformation.Alternatively, when the thermal deformation of the components inside acamera cannot be completely compensated by the axial thermal deformationof the first ring 21 and the second ring 22, the third ring 25 can beutilized to compensate the thermal deformation.

As shown in FIG. 3 again, in this embodiment, the radial connectingmember 26 is a tubular block, and the radial connecting member 26 isintegrally formed with the second ring 22 and extending from the fourthend 222 of the second ring 22 in the radial direction. An end portion ofthe radial connecting member 26 distant from the fourth end 222 of thesecond ring 22 may be assembled with the fifth end 251 of the third ring25. For example, the fifth end 251 of the third ring 25 may be fixedwith the radial connecting member 26 through gluing, threading,engaging, soldering, etc.

In some embodiments, the radial connecting member 26 may have differentconfigurations. For example, the structure of the radial connectingmember 26 may be the same as or similar to the connecting members 23A,23B, 23C shown in FIGS. 3 to 5, but embodiments are not limited thereto.

While the instant disclosure has been described by the way of exampleand in terms of the preferred embodiments, it is to be understood thatthe invention need not be limited to the disclosed embodiments. On thecontrary, it is intended to cover various modifications and similararrangements included within the spirit and scope of the appendedclaims, the scope of which should be accorded the broadestinterpretation so as to encompass all such modifications and similarstructures.

What is claimed is:
 1. A camera capable of automatically compensatingfocal length, comprising: a base; an adjust seat comprising a firstring, a second ring, and a connecting member, wherein the first ring andthe second ring are coaxially sleeved with each other and a distance iskept between the first ring and the second ring, the first ringcomprises a first end and a second end that are axially opposite to eachother, the first end is fixed on the base, the second ring comprises athird end and a fourth end that are axially opposite to each other, thethird end is fixedly connected to the second end of the first ring viathe connecting member, the fourth end, with respect to the third end, isdistant from the second end, and the fourth end has a first couplingpart; and a lens barrel having a second coupling part, wherein thesecond coupling part is correspondingly coupled to the first couplingpart.
 2. The camera according to claim 1, wherein the first ring and thesecond ring have the same coefficient of thermal expansion.
 3. Thecamera according to claim 2, wherein the first ring and the second ringhave the same axial length.
 4. The camera according to claim 1, whereinthe first ring and the second ring have different coefficients ofthermal expansion.
 5. The camera according to claim 4, wherein the firstring and the second ring have different axial lengths.
 6. The cameraaccording to claim 1, wherein the first coupling part comprises a thirdring and a radial connecting member, the third ring comprises a fifthend and a sixth end that are axially opposite to each other, the fifthend is connected to the fourth end of the second ring via the radialconnecting member, the sixth end of the third ring is coupled to thelens barrel.
 7. The camera according to claim 1, wherein the firstcoupling part is an inner thread portion and the second coupling part isan outer thread portion for threading with the inner thread portion. 8.The camera according to claim 1, wherein the connecting member is fixedconnected between an end surface of the second end of the first ring andan end surface of the third end of the second ring.
 9. The cameraaccording to claim 1, wherein the connecting member is between the firstring and the second ring.
 10. The camera according to claim 1, whereinthe connecting member has a groove, the second end of the first ring orthe third end of the second ring is received in the groove.